Pneumatic hammer.



No. 7I2,438. Patented Oct. 28, |902.

C. H. SHAW.

PNEUMATIC HAMMER.

(Applicazian ined .muy 25, 1901.)

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No. 7|2,43a. Patented out. 2s, |902.

c. H. sHAw.

PNEUMATIG HAMMER.

(Application led July 25, 1901.)

(No Mgdel.) 2 sneeuw-sheet 2.

'View on the line 3 3 of Fig. 1.

' UNITED STATES PATENT EEICE.

.oi-IARLES HENRY SHAW,"` OE DENVER, COLORADO.

t PNEUMATIOHAMMER.

SPECIFICATION farming part @farmers Patent No." 712,438, dated canteras, 1902.

l Application liled July 25, 1901i. Serial No. 69.702. (No model.)

To `all whom it may concern: l

Be it known that I, CHARLES HENRY SHAw, a citizen of the United States, residing at Deuver, in the county of Arapahoe and State of Colorado, have invented a new and useful Pneumatic Hammer, of which the followin is-a specification. i

The invention relates to improvements in pneumatic hammers. A The object offthe present invention is t'o improve the construction of pneumatic ham-` mers and to provide a simple, strong, and inexpensive one in which there will be no resistance by the air under pressure to the for`` ward or outward movement of `the plunger,` whereby the force of the blow will be increased. i p A y The inventionconsists in the construction` and novel combination and arrangement of Vparts hereinafter fully described, illustrated in the accompanying drawings, and pointed out in the claims hereto appended.`

4In the drawings, Figure 1 is a longitudinal sectional view of a pneumatic hammer constructed in accordance with thisr invention,` the plunger being at the inner end ofthe casg ing preparatory to delivering a blow. Fig.1 2 is a similar View showing the plunger at the Outer end of the casing after a blow hasbeen delivered. Fig. 3 is a transverse sectional Fig'. 11 is a similar view on the line 4 4 of Fig. 2. n Fig.f 5 is a sectional view on the line 5 5 ot' Fig. 2. Fig. G is a sectional view on the line 6 6 of Fig. 2. Fig. 7 is a transverse sectional View on the line 7 70E Fig. 2. Fig. Sisa sectional view on the line 8 Bof Fig; 2. Figs. 9 and 10 are detail views ofthe valve-casing. Fig. 11 is a longitudinal sectional view of the valve. Fig. 12 is a transverse sectional view of the valve-plug.

Like nuinerals of reference designate corresponding parts in all the figures of the drawings. Y l 1 1 designates a cylindrical main casing having an enlarged upper portion 2 and provided therein with longitudinal apertures, which are preferably formed by grooves inanjinner shell or lining 3, which issecured within the enlarged portion2 of the casing or cylinder 1; but the said passages may be formed in any suitable manner. The casin gis provided 'end of the bore or socket.

between itsends with an interior shoulder formed by enlarging its upper portion, and the inner lining or shell has its inner or lower portion seated against the said shoulder, and it is retained in position' by a valve-casing 4, fitted in the upper or inner end of the main casing or cylinder 1 and provided at its outer end with an annular shoulder 5, which iits against the outer end of the main casing or `cylinder.` The valve-casing is retained in the main casing or cylinder by'a handle 6 and a nut 7. The handle 6 is provided with a socket 8, which tits over the inner or upper end of the "main casing or cylinder and which is provided with exterior screw-threads 9. These screw- Athreads 9 are engaged by the nut `7, which is provided with an annular flange 10, adapted `to engage an annular rib 1l, located on the exterior of the main casing or cylinder, adjacent to the upper end thereof, as clearly shown in Figs. 1 and 2. The nut is introduced on` the main casing or cylinder from the inner or lower end thereof and is moved upward on the same until its interior annular fiange 10 engages the rib 1l. The nut is designed to be provided with a Suitable wrenchreceiving face, and it has notches or teeth at lits edge 12, which are adapted to be engaged by a springactuated bolt 13.

The springactuated bolt 13 is mounted in a socket or bore of an enlargement of the handle, and its Vinner end is engaged by a coiled spring 14,

which is seated against the wall at the inner The spring-a`ctu ated bolt is adapted to lqck the nut in engagement with the handle, and it prevents the nutifrorn becoming loosened by the vibration incident to the Operation of the pneumatic hammer. The handle is provided with a transversely-disposed inlet passage or duct 15" for tbe`intr6duction of air, gas, or other fluid under pressure, and disposed transversely of this inlet passage or duct is a throttle-valve 16, arranged to close the duct or passage and extending into the grip 17 of the handle, which is hollow, and the said throttle` valve is located at one end of the hollow grip in position to be engaged by an inner lever 18. The lever 18 is 'fulcrumed between its ends on a suitable pivot 19, and its outer arm engages the throttle valve, which `is held against the lever by a coiled spring 20. The

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coiled spring 20, which is arranged in the ybore or opening for the valve, is retained therein by a screw-plug 21, and its upper end receives a reduced portion of the valve, as clearly shown in Fig. l. The inner. end of the lever 18 is engaged by a projection 22 of an operating-lever 23, fulcrumed on a suitable pivot 24 and extending outward through a slot 25 of the hollow grip, whereby it is adapted to be readily depressed by t-he operator without removing the hand from the grip of the handle. The operating-lever is adapted to be moved inward to the position illustrated in Fig. 2 of the accompanying drawings, and the valve is moved outward by this operation to carry a reduced portion 26 to the duct or inlet-passage to permit the compressed air or other fluid under pressure to enter the hammer. The operating-lever may be provided at its outer end with a suitable button or head, and the outward movement of its outer arm is limited by a suitable stop 27, arranged to engage the inner face of the hollow grip. The screw-plug, which receives the coiled spring 20, is preferably provided with a socket or recess to form a seat for such spring.

The valve-casing is provided with a transverse aperture 28, in which is arranged an automatic valve 29, which is adapted to be reciprocated automatically by the means hereinafter described when the plunger 30 reaches the limit of its outward movement to introduce the compressed air beneath a shoulder 31 to return the plunger to itsinitial position. The automatic transversely-disposed valve is hollow, being open at one end and provided with a closed end 32 of greater area than its interior, and thesaid hollow valve receives a hollow plug 33, open at its inner'end and closed at its outer end. The air enters the valve-casing at the top through a port 34, and it maintains at all times a constant pressure within the hollow plug and the hollow valve. This internal pressure operates to move the automatic valve outward away from the closed end of the plug to maintain the said automatic valve in the position illustrated in Fig. l ot' the accompanying drawings when there is no presspre on the exterior of the closed end of the valve. As soon as the hammer arrives at the end of its outward movement the pressure ot' the air is applied to the exterior of the closed end of the valve, and as the area of such closed end is greater than the area of the interior of the valve the latter will be moved inward from the position shown in Fig. l to that illustrated in Fig. 2. The valve-plug 33 is provided with an exterior annular groove 33a, and it has apertures 35, located at the annular groove and communicating with its interior, as clearly illustrated in Fig. l2 of the accompanying drawings. The automatic valve 29 is provided with exterior annular recesses or grooves 50 and 51, and it is provided thereat with openings 52 and 53, communicating with the in'- terior of the valve and with Jthe annular recesses or grooves 50 and 51 and adapted to alternately register with the feed-port 34. The valve-casing is provided with interior anuular grooves or passages 54, 55, 56, 57, and 58, the annular groove 56 being arranged at the center of the valve-casing and communicating at the top with the feed-port 34 and at the bottom with apassage 59, which communicates'with a longitudinal passage 37 of the main casing. The annular grooves 54 and 55 are located at oneside of the center of the valve-casing, and the other grooves 57 and 58 are located at the opposite side of the center, as clearly illustrated in Figs. 9 and 10 of the drawings. When the valve 29 is at the limit of its outward movement, as illustrated in Fig. 1, the compressed air enters the feedport 34 and passes through the openings 52 of the valve-casing and through the openings or ports 35 of the valve-plug and enters` the bottom transverse passage 59. It also passes through apertures or ports 36, arranged at the bottom of the annular groove 57 and extending through the bottom of the Valve-casing and communicating with the main casing. The compressed air is thus admitted to the upper end of the plunger,which is moved from the position shown in Fig. 1 to that illustrated in Fig. 2. During this operation airpressureis maintainedin the longitudinalpassage v37, which extends from the valve-casing to an intermediate port 38, located adjacent to the shoulder formed by enlarging the upper portion of the main casing and communicating with an annular groove 39 of the plunger. This establishes a communication between the longitudinal side passage 37 and a similar side passage 39, which extends from the shoulder 40 of the main casing to the valve-casing and introduces the compressed air into the transverse aperture 28 at the closed end of the automatic valve. The area of the exterior of the closed end of the automatic valve being greater than the area of the interior of such end results in a greater pressure on the exterior, and this excess of pressure carries the automatic valve from the position illustrated in Fig. l to that shown in Fig. 2. This movement of the automatic valve shuts off the supply of air to the upper end of the main casing or cylinder and establishes a communication between the inner or upper end of the cylinder and the exterior or outside atmosphere to permit the air to exhaust on the return movement of the plunger. The air from the interior or upper` portion of the main casing or cylinder exhausts through the openings 36 and passes into the annular groove 57 of the valve-casing and then into the annular groove or recess 50 of the automatic valve, which communicates with the annular groove 58. The annular groove 58 communicates With an exhaust-port 4l, through which the air escapes and which-is ICO IZO

` shoulder 41.

opened bythe inward 4or backward recipron `cation ot the automatic valve, as clearly illus- The in-` ward movement. of the automatic val ve also` admits com pressed air into the longitudinal trated in Fig, 4 of the drawings.

passages 42, which conduct the `compressed air to points beneath the shouldel` 3l, formed by the head or enlarged upper end of the plunger. The annular groove 55 of the valvei casing communicates with the annular groove or recess 5l at this time and receives the compressed air from the feed-port 34 andis connected with the longitudinal passages 42 by oppositely-disposed ports or passages 60, arranged as clearly illustrated in Fig. 4, and extending from the said annular groove 55 to the upper ends of the said passages 42. This causesaslowinward movementof the plunger,

which is carried from the position shown in Fig. 2 to that illustrated iuFig. l, whereby` the lower end of the longitudinalpassage 39 is opened and put in communication `with the lowerend of the main casing or cylinder. The main casing or cylinder is provided near its lower end with exhaust-ports 42', which when the plunger is moved inwardpermits the compressed air to exhaust from thelower portion of the main casing and from the .lon-

gitudinal passage 39, thereby relieving the outer closed end of the automatic valve of exterior pressure and permitting the interior pressure to carry the valve outward from the position shown in Fig. 2 to that illustrated in Fig. 1. `This movement of the valve closes the exhaust-port 4l and opens an `exhaustport 43, `which communicates with the annular groove 54 and facilitates the reduction of pressure in the hammer, so that there will be no resistance tothe forward or outward movement of the plunger, as isthe case with hammers maintaining a constant pressure on the., By this construction and operation a blow of increased power is obtained.

This outward movement ofthe automatic` valve returns the parts to their initial `position and establishes acoinmunication between the` source of` supply and the` upper `endof themain `casing or cylinder to again drive the plunger forward or outward. The annular space 48 at the open end ot' the automatic valve communicates with the exterior ot' the casing to relieve the said open. end of the valve of pressureso that there will be no resistance at this end of the valve otherthan` atmospheric pressure, and any suitable aperture may be provided for this purpose.`

The pneumatic hammer, which may be employed for a variety of purposes, as will be readily understood, is adapted to` receive a tool44, which is held in place by a pair of` and the pins, which areprovided at their` outer ends .with heads,have. rou'nded ,inner en'ds and engage the tool, as clearly shown in Figs. 1 and 2. The toolis providedbetween the ends of its shank with a rib-t6, which is rounded, as shown, to permit-the tool to be" readily withdrawn Vfrom andplaced in the pneumatic hammer when the properpressure is applied. The rounded rib is adapted to engage the rounded ends of the pins to force the same outward, and the inner portion of the shank of the tool is received within a sleeve 47. The heads of the pins are received within enlarged portions of the apertures of the casing or cylinder l, and they limit the inward movement of the pins.

What I claim isl. The combination of a casing, a reciprocating plunger, a valve-casing `provided with anaperture and having annular grooves, a

reciprocating automatically-operating valve provided with recesses and Ahaving ports or openings, and a valve-plug loosely fitted in the valve-casing, substantially as described.

3. The combination of` a casing provided with the longitudinal passages 37and 39 and provided with an exhaust-port 42, arranged atthelower portion of the casing and adapted to communicate with the passage 39, said-.casing being also provided with longitudinal passages 42,.communicating at :their inner ends with the upper portion of the casing, a plunger provided with a shoulder and having an annular groove or recess, a hollow reciprocating valve having one of.its ends closed and arranged at the upper or outer endof the passage 39, a plug closing the other end of the automatic valve and reducing the interior area of the same, andmeans for controlling t-he passage of air to the casing, substantially as described.

4. The combination of a casing provided with longitudinal passages, a plunger, avalvecasing provided with an aperture and having annular grooves therein communicating with the said passages, a reciprocating automatic-` ally-operatin g valve having exterior recesses and provided with ports or openings, a valveplug, and meansV for controllingithe passage of air to the casing, substantially as described.

5. The combination of a casing provided withlongitudirral passages 37, 39 and\42,.and having upper and lower exhaust-ports, a'reciprocatin g plunger having an annular groove and provided with a shoulder, a valve-casing having an aperture and "provided with inte- ICO IIO

rior annular grooves, said valve-casing being l In testimony that I claim the foregoing as also provided with ports or openings, an aumy own I have hereto affixed my signature in tomaio valve mount-ed in the valve-easing the presence of nwo Witnesses. and having exterior grooves and providedl CHARLES HENRY SHAW.

5 with ports or openings, and a hollow valvelVitnessos:

plug fitting in the valve and provided with C. F. SCHOFIELD, openings, substantially as described. M. B. FISCHER. 

